How Can I Efficiently Handle Property Value Changes in C# Using Events?

Handling Property Value Changes with Custom Events

In response to the question regarding raising an event upon a property value change, it's important to note that the INotifyPropertyChanged interface operates through events. The interface provides a single event, PropertyChanged, to which consumers can subscribe.

However, a more reliable implementation of INotifyPropertyChanged involves carefully managing the event:

protected void OnPropertyChanged(PropertyChangedEventArgs e)
{
    PropertyChangedEventHandler handler = PropertyChanged;
    if (handler != null)
        handler(this, e);
}

protected void OnPropertyChanged(string propertyName)
{
    OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
}

This approach isolates property change notification methods, simplifies property handling, and fully realizes the INotifyPropertyChanged interface. In addition, you can create a custom event for a specific property change:

protected void OnImageFullPathChanged(EventArgs e)
{
    EventHandler handler = ImageFullPathChanged;
    if (handler != null)
        handler(this, e);
}

public event EventHandler ImageFullPathChanged;

Using the 'CallerMemberAttribute' introduced in .Net 4.5, you can leverage implicit property name invocation:

protected void OnPropertyChanged(
    [System.Runtime.CompilerServices.CallerMemberName] string propertyName = "")
{
    OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
}

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